1. Technical Field
The invention relates to the field of portable computing devices and, more particularly, to using portable computing devices to exchange information using bar codes.
2. Description of the Related Art
Bar codes are used to represent information in a manner that can be easily and automatically read by machines referred to as bar code readers. Accordingly, bar codes are utilized for a variety of different purposes which range from tracking and identifying inventory items to identifying persons. Bar codes can be implemented as single dimension bar codes or as multidimensional bar codes.
In any case, bar code readers, whether implemented as laser scanners, charge-coupled device (CCD) array scanners, or wand scanners, can read a bar code printed on a label. Generally, the bar code reader is able to read the bar code by passing a beam of light over the bar code. The scanner can determine the bars and the spaces between the bars based upon how much light is reflected from the bar code. Notably, bar code readers can scan a given target bar code anywhere from one time per second to over hundreds of times per second. Once the bar code has been read, the bar code scanner can process the raw data.
Bar codes need not be printed on paper or other conventional surfaces. For example, bar codes can be displayed upon display devices such as liquid crystal displays (LCD). LCDs operate by altering the polarity of portions of the screen to allow light to pass through thereby producing areas of contrast on the LCD. Thus, a bar code can be displayed upon the LCD and can be read by a bar code reader.
Conventional devices such as electronic wallets having displays incorporated therein can be programmed to display bar codes upon the display screen of the device. These devices can be programmed to store and display any of several different bar codes which correspond to identification cards the user typically carries on his or her person. Because the electronic wallet can display a given bar code responsive to a user request, the user need not carry the various individual cards if the bar code from the card is stored within the electronic wallet.
Still, such devices are limited to displaying a single bar code responsive to a user request.